Overshot



specification; and in which Patented Dec. 29, 1925.

UNITED STATES ALEXANDER BOYN'ION, OF SAN ANTONIO, TEXAS.

OVERSHOT.

Application filed March 26, 1925.

To all whom t may concern.:

Be it known that I, ALEXANDER BoYNroN, a citizen of the United States. residing at SanAntonio, in the county of Bexar, State of Texas, have invented certain new and useful Improvements in Overshots, of which the following is a specification.

This invention relates in general to overshots and more particularly an overshot designed to use cement for the purpose of binding the tool or obj ect being recovered in the overshot so as to insure the recovery of the lost object.

The object of the invention resides in the provision of an overshot of this character which is of simple and durable construction, which is reliable and effective in operation, which is adapted to provide an extremely strong and dependable union between the lost object and the overshot and yet be capa ble of convenient removal from the lost object when the overshot and the object have been raised to above the ground.

-Other objects and advantages reside in certain novel features of construction, arrangement and combination of parts which will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the acco1npanying drawings forming a part of this Figure l is a sectional view of an overshot constructed in accordance with the present invention and showing the cement employed as'the same appears while the overshot is being lowered into the well,

Figure 2 is a. view similar to Figure l but showing the cement as displaced by a recovered object which has entered the overshot,

Figure 3 is a detail view in section of the frangible sealing or packing elements employed,

Figure 4 is a detail view in section showing the structure of the body of the overshot and one'type of shoe employed at its forward end,

AFigure 5 is a bottom plan view of the lower packing or sealing element, f

` Figure 6 is a top plan view of the element s shown `in Figure 5,

Figure 7 is a top plan view of the upper sea-ling member or packing element, and

Figure S is a view in section of a different type of shoe from vthat shown in Figures l, 2 and 4.

' Referring to the drawings, the numeral l.

Serial No. 18,645.

designates generally the hollow body portion of the overshot. This body portion is made up of two sections which when assembled are of substantially cylindrical form and present a. smooth exterior. Internally the bottom of the overshot is provided with a series of annular ribs or shoulders 2 to provide anchoring means for the cement as will hereinafter appear and to provide means for holding in position the sealing'or packing members to be hereinafter described. The upper end of the hollow body portion l is tapered to an externally threaded reduced end 3 and the lower end of the body portion is also externally threaded and reduced, as indicated at 4f.

A coupling 5 is engaged with the reduced and threaded upper end 3 and is engaged with the lower end of an imperforate section 6. The upper end of the pipe section 6 is connected by a coupling 7 with a perforated pipe section 8.

A shoe 9 is threadedly connected, as at l0, to the reduced and threaded lower end 4 of the hollow body portion l of the overshot. The shoe 9 is formed with V-shaped slots 11 at its forward end, the walls of which are beveled to the inside. These slots facilitate the passage of the tools to be recovered into the hollow body portion. In lieu of the shoe 9 a shoe, designated at l2, and illustrated in Figure 8, may be employed. The shoe 12 is somewhat shorter than the shoe 9 and in' stead of having the slots 1l it is simply inwardly beveled, as indicated at 13. Both the shoes 9 and l2 have a greater external diameter than anyof the elements of the overshot. This feature provides an opening of maximumv size in which thetools to be recovered passyinto the overshot, and it also reduces the area or surface liable to binding engagement with the well casing. The purposes of the shoes 9 and l2 are to facilitate the entrance of the objects to be recovered into the overshot and to aid the coupling 5 in holding the sections of the overshot assembled.

A lower packing or sealing member, designated generally at l5. is provided and is set in a recess 16 provided in the shoe 9 or in a recess 17 provided in the shoe 12, depending on which shoe is used. The packing member engages a shoulder 18 provided by the lower end of the body portion of the overshot and a shoulder on the shoe used, the shoulder of the shoe 9 being designated at 19 and the shoulder of theI shoe 12 being indicated at 20. The packing member 1.5 comprises an open ended cylinder or shell 21 of sheet metal, a trangible bottom plate of sheet metal, such as tin or the like, designated at 22, a covering 23 of wire mesh over shoulders 2. The packing or sealing member 26 comprises a cylindrical body portion 28 of sheet metal or any other suitable. material and annular upper and lower walls 29 and 3() of mesh. The central openings of the walls 29 and 30 are aligned. The edges of the wire mesh walls 29 and 30 are bent over the cylindrical body portion 28 and soldered thereto. The interior of the packing `or sealing member 26 is lilled with steel wool, designated `at 31. Steel wool may also be vplaced between the sealing members 15 or 26 and above the sealing member 26.

In use, the lower packing ring or sealing member 15 is placed in the shoe to be employed and the upper packing ring is placed between the sections ot' the hollow body portion and the hollow body portion is then screwed down into the shoe. rlhe coupling 5 is .then :threaded on the upper portion ol the overshot. Liquid cement is then poured into the overshotthrough the upper 'end of .the coupling 5. The ,cement passes down through the upper packing or sealing member 26 but does not pass through the lower packing or sealing member 15 due to the position of the sheet metal bottom 22. vlPrior to `the pouring Aof ythe cement the desired quantity of steel Wool may be placed in the hollow body of .the overshot. The pipe 6, coupling 7 and perforated pipe 8 are then coupled up and the overshot is lowered down into the well. Unless the object to be recovered is very :short land lies upon the bot-- tom of the well the shoe :9 is .employed since this form of shoe lgreatly facilitates `the passage of the object to be recovered into the overshot. For .the sake of illustration a lost or broken tool, designated at T, is shown in Figure 2 and as indicated the tools :to be recovered pass into the shoe 9 yand ,break through l,the sealing members, the wire mesh as well as vthe thin sheet v metal bottom 22 'being easily broken to permit the passage of the liquid into the linterior of `the overshot. The steel wool in the packing or sealing members, being tightly packed therein, `close around the tool or object being recovered after the same passes through the sealing or packing members and prevents the cement from draining out. Quick set or some other chemical used for the purpose of causing the cement to setl quickly is usually mixed with the cement so that it is necessary to leave the tool in the well only a comparatively short time before the same may be withdrawn. Vhen the overshot is withdrawn the object which has now embedded and set inthe cement is pulled out with the overshot. The purpose of the perforated section or tubing 8 is to balance or equalize the pressure which might force the cement Y up through the tubing and out ot the well when the lluid -is entered in the wall if it were not for the provision of .this perforated. pipe section or tubing. The purpose ot the pipe section .6 is to provide an expansion chamber into which the liquid cement'may be displaced when the object to be removed is i'orced into the cement chamber of the overshot.

elf-ter the overshot with the recovered -tool has 'been raised to above the ground vthe shoe is struck over the threads several times with a hammer and the coupling` 5 is similarly hammered. A pipe wrench is then applied and both the shoe and coupling are unscrewed. Thereafter, a slight tap with the hammer will loosen the two sections of y the body port-ion Aof the .overshot and the same will ,drop volf of the cement. The .cement may then be broken andthe recovered object removed therefrom. Ot course, the overshot would perforn'l .these functions if the mainbody were made in one piece except that it would be practically impossible to remove the .cement and takethe recovered lobject therefrom. ;It is to be understood that any plastic substance which has the property of setting may be used as for instance amalgam, guttafperc-ha, or any lother liquid or plastic setting substance is contemplated as substitutes forcement.

I claim 1. An overshot including a hollow .body portion Aadapted vto receive a. plastic substance, .and a frangible packing member designed to prevent the escape of the -plastic substance and yet admit the passage .oit the object to be recovered into the body portion and into the plastic substance whereby when the plastic substance ha-rdens the object to be recovered will be firmly bound to .the overshot.

2. An overshot including a hollow body portion adapted to receive a plastic substance, a frangible packing member designed to prevent the escape of the plastic substance and yet admit the passage ol the object t'o be recovered into the body portion and into the plastic substance whereby when the plastic substance hardens the object to be recovered will be lirmly bound tothe overshot, and a shoe forwardly of the packing member.

3. An overshot including a hollow body portion adapted to receive a plastic substance, and a frangible packing member designed to prevent the escape of' the plastic substance and yet admit the passage of the object to be recovered into the body portion and into the plastic substance whereby when the plastic substance hardens the object to be recovered will be firmly bound to the overshot, said frangible; packing vmember having plastic means compressible to permit the .passage of the object to be recovered therethrough and expansible to engage said object to prevent the escape of the plastic substance.

4. An overshot including a hollow body portion adapted to receive a plastic substance, and a frangible packing member having frangible end walls and a filling of' steel wool and designed to prevent the escape of the plastic substance and yet admit the passage of the object to be recovered into the body portion and into the plastic substance whereby when the plastic substance hardens the object to be recovered will be firmly bound to the overshot.

5. An overshot including a hollow body portion adapted to receive a plastic substance, and a frangible packing member having wire mesh end walls and a filling of steel wool therein designed to prevent the escape of the plastic substance and yet admit the passage of the object to be recovered into the body portion and into the plastic substance whereby whenthe plastic sub-- stance hardens the object to be recovered will be firmly bound to the overshot.

6. An overshot including a hollow body portion adapted to receive a plastic substance, and a frangible packing member having a lower wall including a frangible sheet metal plate and a covering of wire mesh, an upper wall of wire mesh and a filling of steel wool and designed to prevent the escape of the plastic substance and yet admit the passage of the object to be recovered into the body portion and into the plastic substance whereby when the plastic substance hardens the object to be recovered will be firmly bound to the overshot.

7. An overshot including a hollow body portion adapted to receive a plastic substance, and a frangible packing member designed to prevent the escape of the plastic substance and yet admit the passage of the object to be recovered into the body portion and into the plastic substance whereby when the plastic substance hardens the object to be recovered will be firmly bound to the overshot, said hollow body portion having internal anchoring means for the plast-ic substance.

8. An overshot including a hollow body portion designed to receive a plastic substance and also to receive the object to be recovered, and a pair of' spaced packing members adjacent the lower end of the body portion, the packing members being designed to prevent the loss of the plastic substance and yet permit the tool to pass into the overshot, the upper packing member having openings permitting the plastic substance to pass into the space between the packing members.

9. An overshot including a hollow body portion designed to receive a plastic substance a-nd also to receive the object to be recovered, and a pair of spaced packing members adjacent the lower end of the body portion, the lower packing member having a bottom wall comprising a frangible plate and a covering of wire mesh, an upper wall consisting of wire mesh and a filling of steel wool, the upper packing member having upper and lower walls of wire mesh and a filling of steel wool.

10. An overshot comprising a hollow body portion, a shoe at the forward end of the body portion, frangible packing members adjacent the forward end of the body portion, the body portion being designed to contain liquid cement, an imperforate pipe connected with the upper portion and providing a chamber to receive the cement when the same is displaced by the object to be removed, and a perforated pipe above said imperforate pipe to equalize the pressure upon the cement.

11. In an overshot, a hollow body portion, frangible packing members adjacent the forward end of the body portion, the body por tion being adapted to contain liquid cement,

and means for equalizing the pressure on said cement.

12. ln an overshot, a body portion including sections, a shoe at the forward end of the body portion having threaded engagement with the sections and a coupling at the rear end of the body portion also having threaded engagement with the rear end of the sections, a frangible packing member arranged between the sections, the sections having shoulders holding the packing meinber in position in the assembly, said shoe also having a portion adapted to receive a 'frangible packing member.

ALEXANDER BOYNTON, 

